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' UNITED STATES PATENT FFKQE.

WILLIAM A. STEDMAN, OF NEWPORT, RHODE ISLAND, AND IRA N. STAN- LEY, OF BROOKLYN, NEW YORK.

FURNACE FOR RETORTS.

SPECIFICATION forming part of Letters Patent No. 257,901, dated May 16,- 1882.

V Application filed June 4,1881. (No model.)

To all whom it may concern Be it known that we, WILLIAM A. STEDMAN, of Newport, in the county of Newport and State of Rhode Island, and IRA N. STANLEY, of Brooklyn, Kings county, in the State of New York, have invented certain new and useful Improvements in Furnaces for Gas-Retorts, of which the following isa specification.

Our improvements allow the use of the regenerative principle in a large degree, while presenting a practical and substantial structure, and avoiding most of the objections to regenerative processes as heretofore known.

The furnace proper is of about the ordinary width, except at the base, where it is splayed or drawn together considerably. In the narrowed base or throat thusprodnced we mount a bar made hollow, and receiving steam through apipe from a boiler. (Not represented The upper side of the pipe is perforated to allow the steam to issue in small jets. Proper couplings are provided, which allow the disconnection when it is necessary for any reason to remove the bar. Only a small quan tity of air is admitted to the fuel in the furnace. ThehOt'ig-ases-AargeIycarbonicoxidearising therefrom at a high temperature receive previously-heated air through flues on each side, and the gas produced in the furnace is burned at this higher levelwith the production of great heat for the eflicient action on the retorts. The gaseous products of combustion, after imparting their highest heat to the retorts, descendand travel forward and back, notsimply once, as in the I. N. Stanley patent of 1876, mentioned below, but twice. The traversing forward and back twice is conducted in lines placed at such a distance apart that there is room for liberal air-fines between them. The air is conducted through these flues, thus exposed to the reception of heat from aboveend below, and is raised to a high temperature. Having been actively traversed in this manner, and caused to absorb much of the heat of the spent gases, the fresh air is thrown into the furnace above the fuel, where it combines with the gases and gives an intense heat, and affords a liberal supply of hot flame or intensely-heated gases for bathing the retorts. The arrangement of the rctorts and suitable material, mounted in a bench of ma sonary, B. G is a removable grate-bar placed in the narrow throat at the bottom of the furnace D. The base of the furnace D is car-- rowed gradually and smoothly, so that cinders and clinkers may descend readily. The contracted throat at the base is equipped with a hollow grate-bar, G, which may be removed when required. A coupling and valve, 0, at one end connects a steam-pipe, 0, leading fromaboiler. (Notrepresentcd) Holescinthe bar 0 allow a series of finejets of steam to be thrown upward into the furnace. The steam tends to keep a dull fire and conduces to the success of the apparatus.

The quantity of air admitted through the base of the furnace may be regulated by any suitable register, (not shown,) but should be always less than is required to effect complete combustion.

Carbonic-oxide gas is produced by the partial combustion in thefurnace D, and rises mingled with whatever ordinary gas may be distilled oft from'the coke or other fuel used. It

receives fresh air through lines at the side of the furnace, near the top, and is burned completely, producin g agreat accession to theheat, and pouring a liberal volume of flame or intensely-heated gases up from the top of the furnace among the retorts. The hot products of combustiomafter circulating among the retorts, descend into the horizoutalflneel under the lowest retort and move forward. Near the front of the bench they move laterally ontward and return toward the rear through the parallel flue 0 3 At the back of the bench they descend below theair-flues, and at that lower level come forward again, as indicated by 6 At the front of the furnace they move laterally and then return through the flue 0 At the back they enter the uptake or stack (not shown) and are carried away. The fresh air enters the apparatus through a register (not shown)orotherregulating-valveatd. Itmoves rearward through the flue d. Near the rear it moves laterally and then returns through the flue d At the front it again moves laterally inward and then moves rearward through a flue, 01 At the rear it moves upward and attains a level near the top of the furnace, or

rather of the surface of the deep bed of fuel therein. At this higher level it moves forward in a. flue,d till it reaches a proper point, where it again moves inward and somewhat upward through a short connection into a flue, d, which leads a portion forward and a portion backward and pours the whole into the-furnace through a series of brick passages or nozzles, d The fresh air receives heatat each step through the thin tiles or other partitions above and below. The flues e e have the full temperature due to the gases 011 their emerging from the vicinity of the retorts. The flues c and e have the somewhat lowered but still high temperature due to the further cooling which the products of combustion have received. Both contribute to heating the fresh air as it flows through the flues d and (1 The same contribute also to heat the air at the higher temperature as it flows through the flues (Z andd. The coke or other fuel in the furnace D should be kept up nearly to the level of the mouths of the flues (1*, preferably about twelve ('12) inches below.

Modifications may be made in the proportions, and to some extent in the arrangement, of these parts. The furnace may be placed lower, so that the transverse passages between d and d and between d and d need not slant up so much, or at all. The flues d d which bring the fresh air, and the flues e e and e and e, which conduct the spent products of combustion, may be separated by a thicker mass of masonry; but all such separations tend to obstruct the transmission of heat. The hot gases may be caused to travel back and forward more times than represented; but we esteem four complete traverses, as shown, generally preferable. It is important that a portion be above and another portion below the freshair flues, so as to impart heat thereto as thoroughly as possible. The motion of the air in the several flues, d (1 850., and of the hot gases in the several flues, e e c 0 may be in the reverse direction -that is, the fresh air may be received at the rear and move forward, instead of backward, in the outer flue, and the spent gases may be led out of the furnace at the front and move backward, instead of forward, in the first flue for commencing to heat the air.

Parts of the invention can be used without the whole. We can use more of the steambars or perforated pipes O cconnected to the boiler, so as to'serve both as grate-bars and means for supplying steam to control heat at the bottom of the furnace, and avoid so intense a heat as to injure the fire-bricks adjacent. A valve, 0, gives means for regulating the supply of steam.

We do not claim communicating heat from the outgoing gases toincoming air irrespective of the construction by which this is attained nor do we claim employing steam mingled with the air entering the furnace. Both these features are well known.

\Ve claim as-our invention 1. In a gas apparatus, the combination, with a bench of retorts, A A A with provisions for circulating hot products of combustion around them, of inclosing masonry B, having flues e e e 0, arranged to conduct the products of combustion twice forward and back, and also having flues dd ,forconductingairthrough the space between them, arranged to absorb heat from above and below, substantially as herein specified.

2. In a gas-manufacturing apparatus, the furnace D, formed with orifices d in the side walls, as shown, in combination with longitudinal hot-air flues d d d and connectingpas sages, and with the flues d (1 receiving the air and partially heating the same, all arranged relatively to each other and to the flues e c e e, for conveying the hot products of combustion from the vicinity of the retorts, substantially as herein specified.

3. In combination with the bench of retorts A A 850., surrounding masonry B, and furnace D, the hollow grate-bar O,valved and connected as shown, and having perforations c 0 arranged in the contracted base of the furnace, as and for the purposes herein specified.

In testimony whereof we have hereunto set our hands, at Newport, Rhode Island, this 81st day of May, 1881, in the presence of two subscribing witnesses.

\VM. A. STEDMAN. I. N. STANLEY. Witnesses:

WM. G. \VARD, J. E. BROWN. 

